1. Field of the Invention
This invention relates to a roller skate having a mechanism which selectively controls the wheels in a variety of different modes of operation.
2. Description of Related Art
Roller skates have been in use for well over 100 years. In that time many patents have been obtained for a variety of improvements on the basic arrangement of four wheels connected to a foot support. Among the improvements to roller skates includes a means for preventing the backward movement of the roller skate wheels which is important and in teaching children to roller skate. By providing such a feature, a beginning skater may more easily learn the first step of skating forward without having to be concerned with inadvertently rolling backwards. Backward motion is considerably more difficult for a beginner skater to control than forward motion, and a skate having a forward only mode of operation is known and useful. U.S. Pat. No. 4,553,767 provides an example of a roller skate designed to facilitate learning to roller skate by preventing a pair of wheels from turning in the rearward direction. In particular, the patent describes a roller skate which is selectively switchable between a first unidirectional mode having two wheels prohibited from rotating in a rearward direction and a second free wheeling mode in which all of the wheels may rotate either forward or rearward.
It may also be desirable, when teaching a beginner how to skate, to have a roller skate with wheels that can be selectively made more resistant to rotating. For example, roller skate coaches often begin training children by using roller skates having wheels secured to the axle by nuts and the coaches tighten the nuts to the point where the wheels will not rotate. Then, as the beginner becomes more adept at roller skating, the wheels are increasingly loosened until the wheels are freely rotating. In this kind of device, a separate wrench, which may get lost or misplaced, is required to lock the wheels on such skates.
Having a beginner skater stand on roller skates with non-rotating wheels, allows the skater to become comfortable with the feel of the skates. A restraint on one or more of the wheels, enables the beginner skater to start "skating" by walking on the skates. For more advanced skaters, on the other hand, being able to lock one or more of the wheels can be useful for example, in climbing stairs.
A conventional ratchet and pawl arrangement which prevents rearward motion of the wheels has been used for many years. For example, a loosely pivoting pawl drawn downwardly by the force of gravity is disclosed in U.S. Pat. No. 864,334, issued Aug. 27, 1907. The pawl engages a ratchet mounted to a wheel so that the roller skate will move only in the forward direction. The skate also has an attachment for securing the pawl out of alignment with the ratchet portion so that the wheel may freely move when desired.
More recently, U.S. Pat. No. 4,553,767, issued Nov. 19, 1985, and U.S. Pat. No. 4,932,676, issued Jun. 12, 1990, each disclose a more intricate internal mechanism for preventing backward rotation of at least one wheel of a roller skate. Both designs, however, are susceptible to a variety of problems. For example, the pawl in both arrangements extend below the plane defined by the axles. The pawl engages a plurality of teeth located on an inner surface of the wheel formed by a coaxial channel with the riding surface of the wheel. The channel significantly reduces the strength of the wheel, making it more susceptible to deformation than a solid or internally webbed wheel. Any deformation could prevent the pawl from engaging the teeth, thus defeating the purpose of the whole ratchet and pawl mechanism.
Another problem with the arrangement shown in the above-mentioned patents is the pawl extends below the plane formed by the axles. The pawl is more susceptible to jamming or unwanted movement in either the upward or downward position because of dirt, rocks or mud than any arrangement wherein the pawl never extends below the plane.